package com.itheima.web.servlet;

import com.itheima.pojo.Brand;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/*
替换HttpServlet，根据请求的最后一段路径进行方法分发
 */

public class BaseServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1.获取请求路径
        String uri=req.getRequestURI();// /brand-case/brand/selectAll

        //2.获取最后一段路径
        String methodName=uri.substring(uri.lastIndexOf("/")+1);//  /selectAll

        //3.执行方法
        //3.1获取BrandService字节码对象
        //谁调用我(this所在方法)，我(this)代表谁
        //System.out.println(this);//BaseServlet?HttpServlet?        BrandServlet!
        Class<? extends BaseServlet> cls=this.getClass();
//反射获取方法

        //3.2获取方法Method对象
        try {
            Method method=cls.getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
            //3.3执行
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
}
